Exon 2 Ovar-DRB1 gene polymorphism in the Iranian Sangsari sheep

The major histocompatibility complex (mhc) plays a central role in the control of disease resistance and immune response. extensive genetic diversity in mhc genes provides a valuable source for genetic improvement, via selection, in many domestic animals. exon 2 of the class ii mhc, termed in domestic sheep ( ), has been suggested as important disease resistance and immune response gene. we characterized in dna samples from 138 individuals of a population of the iranian sangsari sheep breed using pcr-rflp. eight alleles were identified among iranian sangsari sheep, including one previously unrecognized allele. eight homozygous genotypeswere observed: andn.genotype was the most common pattern (46 of 138). heterozygous genotypes ( . the observed homozygosity and heterozygosity values were 0.6377 and 0.3623, respectively, vs expected values of 0.220 and 0.779. iranian sangsari population deviate significantly from the theoretical proportions ( is = 0.5283; = 0.0005). in conclusion, pcr-rflp analysis allows rapid identification of types and discrimination of homozygous and heterozygous genotypes. this study indicates that the exon 2 region of the gene is highly polymorphic in the iranian sangsari sheep breed. ovar-drb1 ovis aries ovar-drb1 drb1 a, b, c, d, f, g, h bb ag, cb, cd, bf, and bn) were also observed f p ovar-drb1 ovar-drb1